The theme throughout the book is argument that any jurisdictional assertion by states should be based on the "substantial connection test" to ensure that it is in keeping with the norm of the equality of states and the broader doctrine of comity between states. This is not a new test in the common law and certain aspects of international law but it has been used in a practical capacity to evaluate some jurisdictional claims and recognition of foreign judgments. It argues that the substantial connection test can be used not only as a measure of jurisdictional correctness but as a more holistic and less technical approach to the problem of extraterritorial jurisdiction. The problems that arise with the promotion of the questionable basis for jurisdiction like the 'effects doctrine' from the US and the passive personality principle which is also seen as a dubious basis for a jurisdictional claim can be resolved when states adhere to the substantial connection test. It will distinguish between legitimate and non legitimate claims or assertions of jurisdiction. This book evaluates the key aspects of extraterritorial jurisdiction and focuses on some of the more recent topics in this area that have had a profound effect on international law as a whole. Exerting the power of the state outside the territorial limits of the state is an increasing phenomenon in international law. It comments on the relationship between jurisdiction, sovereignty and international legal order.